45 hrs consider to be as normal working hours.
Beyond 45 hrs of working timing limit as OT.
There is different rate for OT1,OT2,OT3
Fisrt 10 hrs of Overtime is OT1 (45 to 55)
Second 5 hrs of overtime is OT2 (55 to 60)
Last 5 hrs of overtime is OT3 (62 to 65)